What voltage power suply?
 

Hi all,

i've been reading these forums very carefully these past weeks, and it looks like i'm allmost ready to order the parts for my own cnc machine.
So far i decided to make use of the Motion King motors (34HS9801) with a 3 to 1 belt reduction, and gecko 203V drivers.
The output voltage of the power supply, is still my concern.
What output voltage do i need, and will 500VA be enough?

Im pretty sure that some of you MM users have got the same configuration, maybe you guys can tell me wich Voltage works best?

I can't wait to start building. . .

I have the exact same config as you and I bought this transformer:

400VA transformer Objectnr. AN-4442

500VA is plenty, I bought 400VA because I wanted to add a 4th stepper...

Ries

Thx Ries, looks great,
but wich output voltage did you use, 42V? Or did you combine some outputs to create a different output value?

The Motion King 34HS9801 motor is rated 4.1mH, so, if you wire it half-coil, you could use a power supply of up to 65VDC. 42VDC should be perfectly adequate, although I would probably select a 50VDC power supply as a good compromise between excessive heat and maximum speed. A transformer with a 35VAC winding would give you about 50VDC.

I did wire the two 42Volt outputs in parallel to get the desired end voltages that is around 59.5VAC, minus 1.4V of the rectifier bridge you get around 58Volt I believe.

This falls around 7 Volts below the calculated maximum voltage for these steppers according to Maris his formulas. sqrt(4.1)*32=64.8V

In terms of heat generation within my box it falls well within the limits of all components, although I had to create one additional ventilator to pass cool air through the control box from outside through a filter. This properly also has something to do with that my laptop is also mounted in my control box.

Ries

One additional note in response to mike.
My stepper motors will get warm, measured with a simple heat thermometer I get around 45 degrees on the outside of the stepper.
My Gecko's will get a but warmer, but never measured. However I can always touch the cooling plate without problems (for minutes at a time with hand).

Thanks for the reply Mike, but i guess im gonna go with the PSU that Ries uses in his MechMate. This way I'm at least sure that everything will work propper, without over heating.